Device for applying an adhesive to moving surfaces



May 16, 1967 R. WINKLER ETAL DEVICE FOR APPLYING AN ADHESIVE TO MOVING SURFACES 2 Sheets-Sheet 1 Filed June 9, 1965 In van for: RICHRRQ MNKL FR kuR r flumvealsn I firraRA/Ey:

y 16, 1967 R. WINKLER ETAL 3,319,602

DEVICE FOR APPLYING AN ADHESIVE T0 MOVING SURFACES Filed June 9,1965 2 Sheets-Sheet 2 //7 van for: Pun/3A0 M/wa E A/URT bu'lvlv'elfk H M NM firramvera' United States Patent Office 3,319,602 Patented May 16, 1967 3,319,602 DEViCE FOR APPLYING AN ADHESIVE T MOVING SURFACES Richard Winkler, Burgermeister-Wink-Strasse, Rengsdorf,

Germany, and Kurt Dunnebier, Am Birkenhang, Gladhach, Germany Filed June 9, 1965, Ser. No. 462,581 Claims priority, application Germany, July 27, 1964, W 37,251 9 Claims. (Cl. 118253) The invention relates to a device for applying a flowable adhesive to a succession of moving surfaces.

In connection with the manufacture of envelopes of all sizes, flat mailing bags, etc. made of paper in rotary envelope-making machines, it is often necessary to apply to the top flap and the bottom flap of at least partly folded envelopes, etc. a straight or otherwise profiled stripe of adhesive. The application of the adhesive stripe to the envelopes, flat bags, etc.hereinafter referred to collectively as envelopes for the sake of convenienceis usually carried out while the envelopes are moving through the machine making the same and must be applied crosswise of the direction of movement of the envelopes.

The application of the adhesive is generally effected by means of a suitably shaped rotary applicator to which the adhesive is transferred from a feed roller which has on its peripheral wall an adhesive layer of predetermined thickness. The adhesive is applied by the applicator to a predeteremined surface area of the envelope, which is usually supported opposite to the area to which the adhesive is applied. The applicator must have a circumferential velocity which is equal to the speed of travel of the envelope.

When the envelopes to be processed move at a high rate of speed, as is customary in modern plants, difiiculties tend to occur due to adhesive being thrown off from the applicator, which rotates with a correspondingly high speed, and also from the feed roller coacting with the applicator. There is also a certain tendency of the adhesive to foam in the supply container in which it is kept. In practice it is difiicult to trap all the thrown-off adhesive when the machine is in continuous operation. Further, the catch devices tend to render inaccessible the station at which the adhesive is applied.

It is a broad object of the invention to provide a novel and improved device of the general kind above referred to for applying an adhesive in flowable condition to a succession of moving surfaces, which device eliminates or at least substantially reduces the throwing olf of the adhesive from parts of the machine with which the device of the invention is to be used or of which it constitutes a part, and which also eliminates or at least substantially reduces the well-known tendency of the supply of adhesive to foam.

The aforementioned object, feature and advantages of the invention and other objects, features and advantages which will be pointed out hereinafter are attained by rotating the applicator at a circumferential rate of speed which is periodically varied during each revolution of the applicator. The circumferential velocity of the applicator is so selected that it is equal or at least approximately equal to the traveling speed of the envelopes when and while the adhesive is applied thereto, but is considerably lower when adhesive is transferred from the feed roller to the applicator. The circumferential speed of the applicator while adhesive is being applied thereto may be one-half or even one-quarter of the travel speed of the envelopes.

The applicator may be driven by eccentric gears. Each of the eccentric gears has a drive wheel which is fixedly secured thereto or integral therewith, and these drive wheels are held in continuous engagement by means suitable for the purpose. The diameters of the drive wheels are exactly equal to the pitch circles or median diameters of the respective gears and concentric with the same.

One of two eccentric gears may be rotatably supported on a shaft which is secured on a pivotal arm. This arm is pivotal about a shaft which is supported in a suitable part of the frame structure of the machine, such as a side wall thereof. Yieldable means acting upon the arm bias the same into an angular position in which the drive wheel of the eccentric gear supported by the arm is in driving engagement with the drive wheel of the other eccentric gear, whereby the two eccentric gears are maintained in mesh. The shaft on which the arm is pivotally supported is suitably driven, for instance, by means of a chain and gear drive, and in turn drives the drive wheel of the eccentric gear supported by the arm by means of suitable transmission means, such as a gear and chain drive.

Other drive means suitable for obtaining a periodically variable rotational speed of the applicator may also be used, for instance, elliptical gears, a periodically accelerated and retarded chain drive, a differential drive, or a drive using crank guides.

In the accompanying drawing a preferred embodiment of the invention is shown by way of illustration, and not by way of limitation.

In the drawing:

FIG. 1 is a diagrammatic elevational view of the device for applying the adhesive to the envelopes, and

FIG. 2 is a section taken on line 2-2 of FIG. 1.

Referring now to the figures in detail, the path of travel of the envelopes to be processed is indicated at 3. Feed rollers 1 and 2 are disposed below the feed path. All the rollers rotate in the direction indicated by arrows and have a circumferential speed equal to the speed of travel of envelopes along path 3. Counter rollers 4 coact with feed rollers 2. The counter rollers arefareferably springmounted in a conventional manner.

A shaft 5 for the applicator is mounted above feed roller 1 in a side wall 34 of an envelope-making machine, which is not further illustrated, since it does not constitute part of the invention. Side wall 34 or other suitable parts of the frame structure of the machine also support feed rollers 1 and 2.

A holder 6 for the applicator 7 is supported on shaft 5 and secured thereon by suitable means, such as set screws 8. In the event the applicator is of considerable length, several holders 6 may be provided.

Roller 4 may have in the area in which it is to be engaged by applicator 7 a recess or cut 9 to prevent the spilling of adhesive upon roller 1 if one of the envelopes is missing in the feed line. It is of course also possible to equip roller 1 with a suitable washing device.

Shaft 5 further supports an eccentric hub 10 which is fixedly secured to or integral with an eccentric gear 11. Hub 10 is secured on shaft 5 by suitable means, such as a set screw 12. The peripheral rim of hub 10 has a cylindrical running surface 13 which constitutes a drive wheel for gear 11. The diameter of the running surface 13 is exactly equal to the pitch circle or median diameter of the teeth of gear 11 and is concentric with the gear. Gear 11 is in mesh with a similar eccentric gear 14, also integral With or fixedly secured to an eccentric hub formed by a chain wheel 15 and a disk 16. The disk 16 has a cylindrical running surface 17 the diameter of which is exactly equal to the pitch circle or median diameter of gear 14 and is concentric with the same.

The eccentric assembly 14-17 thus formed is rotatable on a pin 18 and secured on the same against lengthwise displacement by a lock ring 19. Bolt 18 is secured at one end by a nut 20 and a washer 21 to an arm or lever 22. Arm 22 is pivotal about the center axis of a shaft 23, which in turn is supported in side Wall 34 of the machine. The free end of arm 22 mounts an extension 24 which is engaged by a loaded tension spring 25. The tension spring pulls the arm in the direction of the arrow-that is, in counterclockwise direction in reference to its pivotal axiswhereby the running surfaces 13 and 17 associated with eccentric gears 11 and 14 are maintained in rotation-transmitting engagement.

Shaft 23 is driven by means of a chain 26 and a gear 27. The rotation of the shaft is transmitted by a gear 28 and a chain 29 to chain gear 15, and thus to the eccentric gears 14 and 11. These gears are driven at a speed such that shaft With the applicator 7 thereon makes one revolution for each envelope which is fed to the device.

The eccentricity of the gears produces a variation 'in the circumferential speed of applicator 7 so that the ratio between the maximum speed and the minimum speed of the applicator is preferably 4:1. The speed of the applicator is at a minimum when adhesive is transferred from a feed roller 30 to the applicator. This position is indicated at 7. Adhesive is supplied to feed roller 30 from a supply tank 31 via a dipping roller 22 and an intermediate roller 33.

If elliptical instead of eccentric gears are used, pivotal arm 22 may be omitted, since elliptical gears do not change their axial distance while rotating.

The device of the invention may be used for individual workpieces and also for continuously running webs or ribbons. The gear assembly as described has the advantage that a very considerably reduced applicator speed during the take-up of adhesive may be obtained in a very simple and inexpensive manner. However, any kind of drive which provides the required speed variations of the applicator during each revolution thereof may be used.

While the invention has been described in detail with respect to a certain now preferred example and embodiment thereof, it will be understood by those skilled in the art, after understanding the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is intended, therefore, to cover all such changes and modifications in the appended claims.

What is claimed is:

1. A device for applying an adhesive to moving surfaces, said device comprising a rotary applicator operatively engageable during each revolution with a moving surface to be coated with the adhesive, supply means for 0 the adhesive operatively engageable with the applicator during each revolution thereof for transferring adhesive to the applicator, and variable speed drive means for rotating said applicator, said drive means imparting to the applicator a rotational speed substantially equal to the rate of movement of the surface when the applicator is engaged with the same for applying the adhesive thereto and a reduced rotational speed when the applicator is engaged with said adhesive supply means.

2. A device according to claim 1, wherein the reduced rotational speed of the applicator is at the most one-half the speed thereof during the application of adhesive to the moving surface.

3. A device according to claim 1, wherein said drive means comprise an eccentric gear train, the eccentricity of said gear train effecting said variation in the rotational speed of the applicator.

4. A device according to claim 3, wherein said eccentric gear train comprises at least two eccentrically supported rotary gears, a drive wheel secured to each gear concentric therewith, movable mounting means supporting one of said eccentric gears and the drive wheel therefor, yieldable means coacting with said movable supported drive wheel for continuously biasing said two drive wheels into motion-transmitting engagement and the gears into mesh, and drive means coupled with said movably supported drive wheel and eccentric gear for rotating the same.

5. A device according to claim 4, wherein the diameter of each of said drive wheels is equal to the pitch circle of the respective eccentric gear.

6. A device according to claim 4, wherein each of said drive wheels is formed by an axial extension of the respective eccentric gear.

7. A device according to claim 3, wherein said eccentric gear train comprises at least two eccentrically supported rotary gears, a drive wheel secured to each gear concentric therewith, movable mounting means supporting one of said eccentric gears and the drive wheel therefor, yieldable means coacting with said movably supported drive wheel for continuously biasing said two drive wheels into motion-transmitting engagement and said gears into mesh, and drive means coupled with said movably supported drive wheel and eccentric gear for rotating the same, one of said eccentric gears being coupled with said applicator for rotation thereof in unison mission means transmitting the rotation of said driving wheel on the power-driven shaft to the drive wheel of the respective eccentric gear.

8. A device according to claim 7, wherein said drive wheel on the respective eccentric gear, said driving wheel on the power-driven shaft and said transmission means constitute a chain drive.

9. A device according to claim 7 and comprising an arm pivotal on one end about the rotational axis of said power-driven shaft, the respective eccentric gear and the drive wheel therefor being supported on the other end of said arm, and wherein said yieldable means bias the drive wheel supported on said arm into engagement with the other drive Wheel.

No references cited.

CHARLES A. WILLMUTH, Primary Examiner.

R. I. SMITH, Assistant Examiner. 

1. A DEVICE FOR APPLYING AN ADHESIVE TO MOVING SURFACES, SAID DEVICE COMPRISING A ROTARY APPLICATOR OPERATIVELY ENGAGEABLE DURING EACH REVOLUTION WITH A MOVING SURFACE TO BE COATED WITH THE ADHESIVE, SUPPLY MEANS FOR THE ADHESIVE OPERATIVELY ENGAGEABLE WITH THE APPLICATOR DURING EACH REVOLUTION THEREOF FOR TRANSFERRING ADHESIVE TO THE APPLICATOR, AND VARIABLE SPEED DRIVE MEANS FOR ROTATING SAID APPLICATOR, SAID DRIVE MEANS IMPARTING TO THE APPLICATOR A ROTATIONAL SPEED SUBSTANTIALLY EQUAL TO THE RATE OF MOVEMENT OF THE SURFACE WHEN THE APPLICATOR IS ENGAGED WITH THE SAME FOR APPLYING THE ADHESIVE THERETO AND A REDUCED ROTATIONAL SPEED WHERN THE APPLICATOR IS ENGAGED WITH SAID ADHESIVE SUPPLY MEANS. 